Welcome to Jezebel After Midnight, in which we indulge in sexy sex talk.

Sex usually involves mouth to mouth, genital to genital, mouth to genital or mouth to nipple stimulation. Oh, and hands (including fingers). But we have so many other surprisingly sexy body parts. If you've ever had someone lick the back of your knee, suck on your toe or lightly tug your earlobe with his or her teeth, you know that unexpected erogenous zones can give you goosebumps.

For me, the spots that are vulnerable are usually the ones that are sensitive and therefore sensual, when touched properly. The inside of the wrist, the nape of the neck, the eyelids. But for some people, a playful nip of the ankle, hot breath on the neck or a long, slow stroke down the spine will get the motor running. Usually the bony joints — elbows, knees — aren't thought of as sexy, where as fleshy parts — armpits, tummies — can be surprisingly erotic. But everyone's different! What are your unexpected erogenous zones? And is it something that you tell your partners? Or do you just let them discover that licking your forehead drives you wild?